Abstract

The development of lasers with very short pulse lengths, of the order of ten femtoseconds, has made it possible to “watch” chemical reactions as they take place. This is because a molecule can be excited and probed by laser pulses in times shorter than the vibrational time-scales of its levels; i. e. before the prepared state gets scrambled by the molecular dynamics. In this way, we can form a wave packet state of the molecule, and track the subsequent motion,^[1] possibly modified by the application of further lasers. Thus we can steer chemical reactions into preselected final products; a process which has potential commercial applications. We can also use information from packet dynamics to investigate molecular surfaces.

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